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A224074 Number of root classes of words in F_2 whose minimal words have length n. 1

%I #8 Oct 03 2016 15:41:40

%S 1,0,0,0,2,0,0,0,13,0,0,0,304,0,0,0,11395,0,0,0,478444,0,0,0

%N Number of root classes of words in F_2 whose minimal words have length n.

%C F_2 is the free group on two generators.

%C a(n) = 0 if n is not divisible by 4.

%H Bobbe Cooper and Eric Rowland, <a href="http://arxiv.org/abs/0909.0561">Growing words in the free group on two generators</a>, Illinois Journal of Mathematics 55 (2011) 417-426.

%H Bobbe Cooper and Eric Rowland, <a href="https://arxiv.org/abs/1307.8216">Classification of automorphic conjugacy classes in the free group on two generators</a>, Algorithmic Problems of Group Theory, Their Complexity, and Applications to Cryptography, edited by Delaram Kahrobaei and Vladimir Shpilrain, Contemporary Mathematics 633 (2015) 13-40.

%Y A224073 is the number of all equivalence classes.

%K nonn,hard,more

%O 0,5

%A _Eric Rowland_, Mar 30 2013

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Last modified May 9 23:14 EDT 2024. Contains 372354 sequences. (Running on oeis4.)